JavaScript that scrapes tweet data from a page on twitter.com

twitter_scraper.js

(function () {
    //Extract latitude and longitude if possible.
    var geo_reg = /(-?\d+.?\d*),(-?\d+.?\d*)/;
    var get_geo = function(tweet) {
        var geo = tweet.find('.tweet-geo-text a').attr('href');
        if (geo) {
            geo = decodeURIComponent(geo);
            geo = geo_reg.exec(geo);
            if (geo) {
                return {
                    'lat': geo[1],
                    'lon': geo[2]
                };
            }
        }
        return {
            'lat': undefined,
            'lon': undefined
        };
    };
    
    //Convert an array of strings into a line of CSV.
    //Escapes double-quotes and error-prone whitespace.
    var csvfy = function (row) {
        return row.map(function (cell) {
            if (cell) {
                cell = cell.toString()
                    .replace(/"/g, '""')
                    .replace(/\r\n/g, " ")
                    .replace(/\n/g, " ")
                    .replace(/\t/g, " ");
            }
            return cell ? '"' + cell.toString().replace('"', '""') + '"' : '""';
        }).join(',');
    };
    
    var tweets = $('.tweet').map(function () {
        var tweet = $(this);
        var geo = get_geo(tweet);
        return {
            id: tweet.data('tweet-id'),
            user_id: tweet.find('[data-user-id]').data('user-id'),
            username: tweet.find('.username').text(),
            text: tweet.find('.tweet-text').text(),
            full_name: tweet.find('.fullname').text(),
            created_at: tweet.find('[data-time]').data('time'),
            latitude: geo.lat,
            longitude: geo.lon
        };
    });
    
    //Build the CSV file
    var lines = [];
    lines.push(csvfy(["id", "user_id", "username", "full_name", "created_at", "latitude", "longitude", "text"]));
    tweets.each(function () {
        lines.push(csvfy([this.id, this.user_id, this.username, this.full_name, this.created_at, this.latitude, this.longitude, this.text]));
    });
    //Add BOM at the start to make Excel read UTF-8
    var csv = "\ufeff" + lines.join("\n");
    
    //Download it
    var uri = "data:text/csv;charset=utf-8," + encodeURIComponent(csv);
    window.location.href = uri;
})();